Long-term Climate Mitigation Research Articles

A cost-effective climate mitigation pathway for China with co-benefits for sustainability

Climate mitigation policies have broad environmental and socioeconomic impacts and thus underpin progress towards the United Nations Sustainable Development Goals (SDGs). Through national-scale integrated modeling, we explore the spillover effects of China’s long-term climate mitigation pathways (CMPs) on achieving all 17 SDGs, and then identify a cost-effective CMP for China with co-benefits for sustainability. Our analysis indicates that the 9 original CMPs and 180 bundled CMPs can both substantially boost the SDGs, resulting in an increase of 6.33–8.86 and 5.90–9.33 points in overall SDG score (0=no progress, 100=full achievement) by 2060, compared to the Reference pathway of 70.75 points, respectively. The identified cost-effective CMP deals with the trade-offs among sustainability, CO2 emissions and mitigation cost, and maximizes the synergies between them. This CMP can inform future directions for China’s policy-makers to maximize the potential synergies between carbon neutrality and long-term sustainable development.

Agriculture-driven deforestation in Ecuador's Mache-Chindul Ecological Reserve: The farmers' perspective

Tropical rainforests serve as invaluable global carbon stocks with long-term climate mitigation potential and important ecosystem functions and biodiversity. Recent scholarship has identified agriculture as the main driver of tropical rainforest deforestation worldwide, yet effective policy action needs to understand why farmers continue to clear land, beyond broad-brush attributions of blame. This study highlights the constellation of social forces that drive deforestation in a subsection of the Mache Chindul Ecological Reserve (REMACH) in northwest Ecuador. Rather than simply assuming that farmers are either indifferent to or ignorant of the effects of deforestation, we highlight the perspective of farmers themselves as they reflect on, both, their relationship with other key actors and the broader contextual factors informing their own land-use decisions. We surveyed 70 rural households using a 45-question data collection tool, conducted semi-structured interviews with key stakeholders such as local conservation practitioners and community elders, employed participant observation and reviewed government documents.We find that colonist farmers who live in and around the REMACH clear land because they view doing so as their most reliable means of securing a livelihood for themselves and their children in a context of political and economic hardship and uncertainty. A history of government incentives to clear land, a deeply ambiguous land tenure system, and a sudden influx of externally-funded conservation NGOs to the region have all contributed to exclude farmers from the decision-making process, while simultaneously exacerbating the conditions that make deforestation farmers' most practical option—despite their awareness of its environmental impact. The data underscore that locals are, in fact, highly invested in the idea of conserving a healthy environment for future generations, but are nonetheless driven to act against this interest by their own precarity. By helping governmental and non-governmental conservation practitioners better understand farmers’ land-use decisions, the study reframes the latter group not as the problem, but as vital future partners.

Opportunities beyond CO2 for climate mitigation

Opportunities beyond CO2 for climate mitigation

A gap in nitrous oxide emission reporting complicates long-term climate mitigation

Nitrous oxide (N2O) is an important greenhouse gas (GHG) that also contributes to depletion of ozone in the stratosphere. Agricultural soils account for about 60% of anthropogenic N2O emissions. Most national GHG reporting to the United Nations Framework Convention on Climate Change assumes nitrogen (N) additions drive emissions during the growing season, but soil freezing and thawing during spring is also an important driver in cold climates. We show that both atmospheric inversions and newly implemented bottom-up modeling approaches exhibit large N2O pulses in the northcentral region of the United States during early spring and this increases annual N2O emissions from croplands and grasslands reported in the national GHG inventory by 6 to 16%. Considering this, emission accounting in cold climate regions is very likely underestimated in most national reporting frameworks. Current commitments related to the Paris Agreement and COP26 emphasize reductions of carbon compounds. Assuming these targets are met, the importance of accurately accounting and mitigating N2O increases once CO2 and CH4 are phased out. Hence, the N2O emission underestimate introduces additional risks into meeting long-term climate goals.

CCUS deployment under the U.S. 45Q tax credit and adaptation by other North American Governments: MARKAL modeling results

In 2018, U.S. Congress passed the Bipartisan Budget Act, known as 45Q [H.R. 3761], expanding the corporate income tax credit for carbon capture utilization and storage (CCUS). 45Q provides a performance-based tax credit for carbon capture projects of $30/ton of carbon dioxide (CO2) (tCO2) for anthropogenic CO2 going to enhanced oil recovery (EOR), and $50/tCO2 if going to straight storage. There are several conditions; for example, there is a 12-year time limit on tax credits for a new plant that commences construction before 2024 [H.R. 3761].This study aims to test the incremental impact of the 45Q tax credits on CCUS deployment, CO2-EOR, and power generation technological changes for North American (the United States, Canada, and Mexico) long-term energy system development. The scenario results show that offering a 12-year CO2 storage subsidy provides the motivation needed for CCUS investment during the 12-year subsidy period, and the benefits of such investment can be sustained over the 40-year lifetime under CO2 taxation. The modeling results show that carbon capture generation replaces uncontrolled fossil-fueled power, not new or existing renewables, so power generation and corresponding emission reductions from renewables remain unaffected by the availability of 45Q in the United States. Our scenario with CCUS technological learning indicates that CCUS could play a very important role under stringent environmental constraints. Thus, accelerated support and funding for the large-scale CCUS demonstrations is important for the execution of both short- and long-term climate mitigation goals.Given the significant role of the United States, Canada, and Mexico on the world energy system, our results represent an important contribution to the study of global energy trends.

Public Policy and Incentives for Socially Responsible New Business Models in Market-Driven Real Estate to Build Green Projects

The construction industry and the built environment accounts for 38% of global greenhouse gases. Significant efforts are being implemented across stakeholder categories to provide supportive guidelines and ways to address the negative impact; however, market developers need to be engaged to create the scale of impact due to large portfolios. Unfortunately, the short-term interests of private developers in real estate are to maximize profits and not to invest in long-term climate mitigation strategies. This paper will address the barriers and opportunities to incentivize, regulate real estate developers, and account for the market to adopt the lens of the B-Corp movement’s triple bottom line business practices, using business to address social and environmental challenges. Academically, accepted theories addressed through a literature review will be analyzed by a socially-oriented developer in Montreal and demonstrated through an eco-district case study. This study will identify the key stakeholders and address the life cycle thinking process to tackle the carbon impacts in the building development sector through the lens of real estate developers. This literature review will be complemented by the empirical study of one of the authors being a private developer, to link academic best practices with the market realities of real estate development. The findings of the process will outline possible solutions to real estate development that suggest cities have the opportunity to play the role of an educator, mediator, regulator, and incentivizing body to private real estate developers. Generally, critical factors of collaboration and capacity building through business modelling lists of barriers and opportunities could promote positive adoption opportunities for large-scale green development projects with a high impact on climate mitigation strategies, which could transform how the construction industry adapts to building green and socially inclusive communities.

Simulating land use and land cover change under contrasting levels of policy enforcement and its spatially-explicit impact on tropical forest landscapes in Ecuador

This study simulates the future impact of land use and land cover (LULC) change and the enforcement of policy bundles on the multi-functionality of tropical forest landscapes. It focusses on the Northern Ecuadorian Amazonas (NEA) which is characterised by high biodiversity and endemism but at the same time is threatened by deforestation and unsustainable land use practices. Scenario simulations mimic LULC change during 2016–2030 at canton-level (area: 2,146 km²) combining explorative with policy-screening components. Scenarios NATIONAL(+)POLICY, NATIONAL(-)POLICY, REGIONAL(+)POLICY, and REGIONAL(-)POLICY are contrasted by varying deforestation trends (high regional demand for agricultural products vs. national-level structural transformations) and the enforcement/ non-enforcement of policy bundles on forest protection, reforestation and restoration. An indicator-based impact assessment analysed in a spatially-explicit fashion for each scenario in 2030 (i) the evolution of agricultural and forestry-related LULC change trajectories, (ii) future hotspots of deforestation, (iii) remaining forest core zones (FCZ) as key element of habitat integrity, and (iv) the provisioning of long-term carbon sinks. Key findings reveal that only NATIONAL(+)POLICY, as the combination of enforced policy bundles and simulated national LULC change trend extrapolating the long-term reference period 1990–2016, lead to an expansion of forest areas and a 2% carbon stock gain in 2030 compared to 2016. When assuming a linear continuation of this trend, it requires 96 years to reach a similar carbon stock level compared to the reference year 1990. Farm area expansion will continue to affect protected forests in case of scenarios NATIONAL(-)POLICY and REGIONAL(-)POLICY but will be avoided in NATIONAL(+)POLICY and REGIONAL(+)POLICY. The simulated persistence of many farming areas reveals that the likelihood to reforest existing agricultural patches will be rather low. Against expectations, scenario NATIONAL(+)POLICY which assumes net zero deforestation by 2030 led to a high level of FCZ fragmentation contrasting its carbon sink potential (27,971 Mio. Mg ha−1) which performed best among all scenarios. Our study depicts a mismatch of future LULC change realities compared to the anticipated future achievements of the Ecuadorian land use policy framework. The simulated variability of forest change patterns (deforestation, reforestation) and farming trajectories (diversification, intensification, rotation) further suggests to foster more cross-sectoral policy approaches that acknowledges the hybrid role of local stakeholders who can be farmers and forest users at the same time. Our study shows that focusing on preserving carbon stocks and their long-term climate mitigation potential only while neglecting other important ecosystem functions or biodiversity can be a short-sighted policy goal if not accompanied by rural development programmes. We further conclude that scenario-based assessments should become an integral part of multi-stakeholder interactions across relevant levels of decision-making. This can support long-term sustainable land use management which is not only relevant for the case of the Northern Ecuadorian Amazons region but for many other landscapes in transition.

Mitigating climate disruption in time: A self-consistent approach for avoiding both near-term and long-term global warming

The ongoing and projected impacts from human-induced climate change highlight the need for mitigation approaches to limit warming in both the near term (<2050) and the long term (>2050). We clarify the role of non-CO2 greenhouse gases and aerosols in the context of near-term and long-term climate mitigation, as well as the net effect of decarbonization strategies targeting fossil fuel (FF) phaseout by 2050. Relying on Intergovernmental Panel on Climate Change radiative forcing, we show that the net historical (2019 to 1750) radiative forcing effect of CO2 and non-CO2 climate forcers emitted by FF sources plus the CO2 emitted by land-use changes is comparable to the net from non-CO2 climate forcers emitted by non-FF sources. We find that mitigation measures that target only decarbonization are essential for strong long-term cooling but can result in weak near-term warming (due to unmasking the cooling effect of coemitted aerosols) and lead to temperatures exceeding 2 °C before 2050. In contrast, pairing decarbonization with additional mitigation measures targeting short-lived climate pollutants and N2O, slows the rate of warming a decade or two earlier than decarbonization alone and avoids the 2 °C threshold altogether. These non-CO2 targeted measures when combined with decarbonization can provide net cooling by 2030 and reduce the rate of warming from 2030 to 2050 by about 50%, roughly half of which comes from methane, significantly larger than decarbonization alone over this time frame. Our analysis demonstrates the need for a comprehensive CO2 and targeted non-CO2 mitigation approach to address both the near-term and long-term impacts of climate disruption.

An open-source tool for visualization of climate mitigation scenarios: Mipplot

Synthesizing and communicating knowledge on climate change to policymakers and stakeholders is often difficult due to the complexity and diversity of underlying research. As a “translation” instrument, we present the mipplot tool, an open-source R package that can be used to visualize data of long-term climate mitigation scenarios. With simple commands and under a user-friendly language platform, this tool generates plots in multiple languages for any scenario dataset following the data submission format of the Integrated Assessment Modeling Consortium. The plots can be generated both by function call in R environment and by an interactive interface in a web browser environment, which offers greater flexibility of inputs and suits both experts and non-experts. Moreover, its capability of specifying aggregation rules and different display languages extends its applicability to a broader range of users.

Perceptions and realities of hydroclimatic change affecting Guyanese rice farming

This study explores small farmers' perceptions of changes in climate across Guyana’s rice-producing regions. Qualitative, primary data were collected from a random sample of 189 small farmers, supplemented with 28 key informants, from across Guyana’s five main rice-producing regions. The most prevalent perception related to precipitation among farmers is an increase in rainfall year-round (56%), while for informants, it is an increase in rainfall intensity (81%). When considering the atmospheric conditions of temperature and humidity, farmers (88%) and informants (96%) overwhelmingly perceive warmer conditions. Considering weather and climate volatility, farmers (72%) and informants (82%) most prevalently perceive an increase in excess rainfall/flooding, but secondly, farmers (58%) and informants (71%) communicated a perceived increase in drought. Secondary quantitative hydroclimate data support the perception of a wetter climate, and to some degree, increased hydroclimatic volatility. Precipitation is critical to rice cultivation, and the data sets, combined, signal a wetter Guyanese climate, which has major economic implications for small farmers, the broader rice industry, and the economy of Guyana. However, granularity in farmers’ perceptions suggests a need for more detailed hydroclimate monitoring across Guyana. Thus, strengthening the Guyanese Hydrometeorological Service to support improved spatial and temporal monitoring and collection of primary weather data would be a wise investment in short- and long-term climate mitigation efforts.

Implications of Japan’s long term climate mitigation target and the relevance of uncertain nuclear policy

ABSTRACT Achieving long-term climate mitigation goals in Japan faces several challenges, starting with the uncertain nuclear power policy after the 2011 earthquake, the uncertain availability and progress of energy technologies, as well as energy security concerns in light of a high dependency on fuel imports. The combined weight of these challenges needs to be clarified in terms of the energy system and macroeconomic impacts. We applied a general equilibrium energy economic model to assess these impacts on an 80% emission reduction target by 2050 considering several alternative scenarios for nuclear power deployment, technology availability, end use energy efficiency, and the price of fossil fuels. We found that achieving the mitigation target was feasible for all scenarios, with considerable reductions in total energy consumption (39%–50%), higher shares of low-carbon sources (43%–72% compared to 15%), and larger shares of electricity in the final energy supply (51%–58% compared to 42%). The economic impacts of limiting nuclear power by 2050 (3.5% GDP loss) were small compared to the lack of carbon capture and storage (CCS) (6.4% GDP loss). Mitigation scenarios led to an improvement in energy security indicators (trade dependency and diversity of primary energy sources) even in the absence of nuclear power. Moreover, preliminary analysis indicates that expanding the range of renewable energy resources can lower the macroeconomic impacts of the long term target considerably, and thus further in depth analysis is needed on this aspect. Key policy insights For Japan, an emissions reduction target of 80% by 2050 is feasible without nuclear power or CCS. The macroeconomic impact of such a 2050 target was largest without CCS, and smallest without nuclear power. Energy security indicators improved in mitigation scenarios compared to the baseline.

Gaps between pre-2020 climate policies with NDC goals and long-term mitigation targets: analyses on major regions

The year 2020 will be the first year for global stocktake on carbon mitigation, whether the current policies are on track to meet the NDC goals would become a highly focused issue, and further enhancement on national NDCs under long-term climate mitigation target would also attract much attention by then. Comparing the actual CO2 emissions in 2017 and the expected emissions under NDC goals, this paper analyzes the gaps between current mitigation progress and NDC goals for major region including the US, EU, China and India, and energy system optimization has been conducted to explore possible plans to close these gaps. In addition, this paper compares CO2 emission pathways under global NDCs and 2-degree target, pointed that existing NDCs are not enough to realize 2-degree target, by 2030, additional mitigation of about 10 Gt CO2 is required for global energy system, which indicating enhanced NDCs should be designed as soon as possible to reduce risks and cost in long-term mitigation actions.

Japan's long-term climate mitigation policy: Multi-model assessment and sectoral challenges

Japan is the sixth largest greenhouse gas emitter in 2016 and plays an important role to attain the long-term climate goals of the Paris Agreement. One of the key policy issues in Japan's energy and environmental policy arena is the energy system transition to achieve 80% emissions reduction in 2050, a current policy goal set in 2016. To contribute to the ongoing policy debate, this paper focuses on energy-related CO2 emissions and analyzes such decarbonization scenarios that are consistent with the government goals. We employ six energy-economic and integrated assessment models to reveal decarbonization challenges in the energy system. The modeling results show that Japan's mitigation scenarios are characterized by high marginal costs of abatement. They also suggest that the industrial sector is likely to have a large final energy share and significant residual emissions under the 80% reduction scenario, though it is generally thought that the transport sector would have large decarbonization challenges. The present findings imply that not only energy policy but also industrial policy may be relevant to the long-term environmental target. Given the high marginal costs exceeding those of negative emissions technologies that could place a cost ceiling, further model development would be crucial.

Lessons from co-impacts assessment under the Mitigation Action Plans and Scenarios (MAPS) Programme

The MAPS Programme has been active in Brazil, Chile, Colombia and Peru in supporting the development of an evidence base to inform the processes involved in climate mitigation policy-making. The programme combines detailed quantitative analysis with an extensive stakeholder engagement process to provide policy and decision makers with the information required for long-term climate mitigation planning.In recognition of the critical need to consider the developmental context and agenda in climate policy-making, the projects undertaken in these countries have experimented with various types of assessments of developmental impacts at both the macro and micro levels. These impacts have been collectively termed co-impacts to reflect the fact that these may be either positive or negative. In this article the value and challenges associated with co-impacts work for climate mitigation policy are considered. The value of including co-impacts analysis in the MAPS processes included increased stakeholder buy-in, making the case for mitigation action, informing INDCs and the prioritization of particular mitigation actions. Challenges include those associated with obtaining locally relevant data, the selection and operation of appropriate macro-economic models and analytical approaches and working with multidisciplinary teams.The article concludes by making some suggestions to optimize co-impacts work, through reference to other bodies of literature. The authors highlight that this article is situated within a dominant approach to climate mitigation policy work in developing countries, which implicitly places the non-climate benefits of any action as secondary to the primary benefit of climate change mitigation and constructs an artificial separation of policy formulation and implementation. Practitioners are encouraged to reflect on the implications of these considerations in future efforts.Policy relevanceOne of the primary challenges to advancing climate mitigation policy in developing countries is that of perceived relevance: near-term development priorities are overwhelming. Identifying, understanding and engaging with the co-impacts of mitigation actions has emerged as one way of addressing this challenge. Although still at an experimental phase, experience with co-impacts analysis in the MAPS countries provides some useful lessons in how to develop this area of work.

Implication of Paris Agreement in the context of long-term climate mitigation goals.

The Paris Agreement confirmed the global aim to achieve a long-term climate goal, in which the global increase in mean temperature is kept below 2 °C compared to the preindustrial level. We investigated the implications of the near-term emissions targets (for around the year 2030) in the context of the long-term climate mitigation goal using the Asia-Pacific Integrated Model framework. To achieve the 2 °C goal, a large greenhouse gas emissions reduction is required, either in the early or latter half of this century. In the mid-term (from 2030 to 2050), it may be necessary to consider rapid changes to the existing energy or socioeconomic systems, while long-term measures (after 2050) will rely on the substantial use of biomass combined with carbon capture and storage technology or afforestation, which will eventually realize so-called negative CO2 emissions. With respect to the policy context, two suggestions are provided here. The first is the review and revision of the nationally determined contributions (NDCs) in 2020, with an additional reduction target to the current NDCs being one workable alternative. The second suggestion is a concrete and numerical mid-term emissions reduction target, for example to be met by 2040 or 2050, which could also help to achieve the long-term climate goal.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-016-3235-9) contains supplementary material, which is available to authorized users.

Applying personal carbon trading: a proposed ‘Carbon, Health and Savings System’ for British Columbia, Canada

Addressing climate change requires the synergy of technological, behavioural and market mechanisms. This article proposes a policy framework that integrates the three, deploying personal carbon trading as a key element within a policy portfolio to reduce personal carbon footprints. It draws on policy and human motivation literatures that address the behavioural changes that may be needed in the context of a long-term threat such as climate change. This proposal builds on an analysis of the British Columbia carbon tax, international examples of carbon pricing instruments and strategies for behavioural change such as social networks, loyalty management, mobile apps and gamification. Interviews were conducted with experts in financial services, energy conservation and clean technology, as well as with specialists in climate, health and taxation policy. Their input, together with a review of the theoretical literature and practical case studies, informed the proposed design of a Carbon, Health and Saving System for promoting individual engagement and collective action by linking long-term climate mitigation measures with short-term personal and social goals, including health, recreation and social reinforcement.Policy RelevanceThis article identifies areas for climate policy innovation and recommends policies that can support, promote and enable personal carbon budgeting and collective action. Although this study is focused on British Columbia, both the input provided by key opinion leaders and the proposed framework are applicable to other jurisdictions.This policy proposal shows how personal carbon trading could work in the context of a Canadian province with an existing climate mitigation policy. It also specifies a minimum viable product approach to establishing the economic, social and technological foundations for personal carbon trading.The Carbon, Health and Saving System identifies the technologies and stakeholders needed to implement personal carbon trading, and offers the possibility of motivating a widespread conscious human response in the event that carbon taxation proves insufficient to generate economic adaptation in a changing climate.

Simulating effects of grazing on soil organic carbon stocks in Mongolian grasslands

Grassland degradation is a major issue in many parts of the world. Rehabilitation of areas that have been degraded by overgrazing can potentially accumulate soil carbon, but there have been few studies in the vast grasslands of Mongolia. Here, we calibrated and validated Century model with 618 measurements from a soil inventory covering four grassland types in a forest steppe region of Mongolia. Soil organic carbon (SOC) simulated by Century largely agreed with the observational dataset and the sign of SOC response to intensive grazing. We employed the calibrated model to assess SOC accumulation under reduced grazing intensity scenarios, and the projected accumulation rates were 22.0–36.9gCm−2yr−1 in the near term (2012–2035). These results imply that reducing the intensity of grazing may be an effective strategy for restoration of degraded grasslands, which can be implemented by reducing livestock numbers and/or by changing the timing and duration of grazing events. Moreover, the simulated SOC accumulation was mainly determined by a conceptual slow pool, which was not supported by experimental observations in similar soils. Therefore, evaluating the long-term climate mitigation through soil carbon accumulation in degraded grasslands still warrants further attention.

Business-as-Unusual: Existing policies in energy model baselines

Baselines are generally accepted as a key input assumption in long-term energy modelling, but energy models have traditionally been poor on identifying baselines assumptions. Notably, transparency on the current policy content of model baselines is now especially critical as long-term climate mitigation policies have been underway for a number of years. This paper argues that the range of existing energy and emissions policies are an integral part of any long-term baseline, and hence already represent a “with-policy” baseline, termed here a Business-as-Unusual (BAuU). Crucially, existing energy policies are not a sunk effort; as impacts of existing policy initiatives are targeted at future years, they may be revised through iterative policy making, and their quantitative effectiveness requires ex-post verification. To assess the long-term role of existing policies in energy modelling, currently identified UK policies are explicitly stripped out of the UK MARKAL Elastic Demand (MED) optimisation energy system model, to generate a BAuU (with-policy) and a REF (without policy) baseline. In terms of long-term mitigation costs, policy-baseline assumptions are comparable to another key exogenous modelling assumption — that of global fossil fuel prices. Therefore, best practice in energy modelling would be to have both a no-policy reference baseline, and a current policy reference baseline (BAuU). At a minimum, energy modelling studies should have a transparent assessment of the current policy contained within the baseline. Clearly identifying and comparing policy-baseline assumptions are required for cost effective and objective policy making, otherwise energy models will underestimate the true cost of long-term emissions reductions.

Parallel Pursuit of Near-Term and Long-Term Climate Mitigation

Two separate treaties are needed to address the unique climate roles of long-lived versus medium- and short-lived pollutants.

Air Quality Impacts of Climate Mitigation: UK Policy and Passenger Vehicle Choice

In 2001-2002 the UK began taxing vehicles according to CO2 emission rates. Since then, there has been a significant increase in consumer choice of small cars and diesel engines. We estimate CO2 reductions and air quality impacts resulting from UK consumers switching from petrol to diesel cars from 2001 to 2020. Annual reductions of 0.4 megatons (Mt) of CO2 and 1 million barrels of oil are estimated from switching to diesels. However, diesels emit higher levels of particulate matter estimated to result in 90 deaths annually (range 20-300). We estimate 570, 460, and 0 additional deaths per Mt of CO2 abated, for Euro III, Euro IV, and post-Euro IV emission class vehicles, respectively. CO2 policies are suspected to have contributed substantially to diesel growth, but the magnitude of impact has yet to be quantified rigorously. To the extent that CO2 policies contribute to diesel growth, coordinating CO2 controls with tightening of emission standards would save lives. This research shows that climate policy, while reducing fuel use and CO2, does not always ensure ancillary health benefits. Lessons from the UK can help inform policies designed elsewhere which strive to balance near-term ambient air quality and health with long-term climate mitigation.